JPS5593392A - Subscriber circuit - Google Patents

Subscriber circuit

Info

Publication number
JPS5593392A
JPS5593392A JP247479A JP247479A JPS5593392A JP S5593392 A JPS5593392 A JP S5593392A JP 247479 A JP247479 A JP 247479A JP 247479 A JP247479 A JP 247479A JP S5593392 A JPS5593392 A JP S5593392A
Authority
JP
Japan
Prior art keywords
circuit
terminal
circuits
exchange
polarity
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP247479A
Other languages
Japanese (ja)
Inventor
Kunio Nagashima
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Nippon Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP247479A priority Critical patent/JPS5593392A/en
Publication of JPS5593392A publication Critical patent/JPS5593392A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/005—Interface circuits for subscriber lines

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Devices For Supply Of Signal Current (AREA)
  • Interface Circuits In Exchanges (AREA)

Abstract

PURPOSE:To avoid the current flowing directly to the switch element inverting the polarity, to make small and light the circuit and to make easy for circuit integration, by performing the 2-4 wire conversion using three winding transformer with the addition and subtraction operation by the operational amplifier. CONSTITUTION:The audio signal fed to the first terminal 200 and the second terminal 201 is converted into unbalanced ground with the differential amplifying circuit 202, and the output is outputted to the exchange circuit by feeding it to the third terminal 203 via the subtraction circuit 205. On the other hand, the audio signal fed to the fourth terminal 204 in unbalanced ground from the exchange circuit is converted into balanced ground signal with the in-phase addition circuit 206 and the inversion amplifying circuit 209, it is delivered to the subscriber connected between the terminals 200 and 201 and fed to the exchange circuit via the circuits 202 and 205. Further, the current flowing to the switch elements 207 and 210 directly inverting the polarity is avoided with the operational amplifiers 212, 218 of the circuits 206 and 209 to make small and light the subscriber circuits and to make easy for the circuit integration.
JP247479A 1979-01-10 1979-01-10 Subscriber circuit Pending JPS5593392A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP247479A JPS5593392A (en) 1979-01-10 1979-01-10 Subscriber circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP247479A JPS5593392A (en) 1979-01-10 1979-01-10 Subscriber circuit

Publications (1)

Publication Number Publication Date
JPS5593392A true JPS5593392A (en) 1980-07-15

Family

ID=11530318

Family Applications (1)

Application Number Title Priority Date Filing Date
JP247479A Pending JPS5593392A (en) 1979-01-10 1979-01-10 Subscriber circuit

Country Status (1)

Country Link
JP (1) JPS5593392A (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5332605A (en) * 1976-09-03 1978-03-28 Thomson Csf Telephone line circuit

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5332605A (en) * 1976-09-03 1978-03-28 Thomson Csf Telephone line circuit

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